Answer this question truthfully
### Question: What causes Atrial myxoma?
### Response: A myxoma is a primary heart (cardiac) tumor. This means that the tumor started within the heart. Most heart tumors start somewhere else. A tumor that originates elsewhere is called a metastatic tumor to the heart.
Primary cardiac tumors are rare. Myxomas are the most common type of these rare tumors. About 75% of myxomas occur in the left atrium of the heart, usually growing out of the wall that divides the two upper chambers of the heart. The rest are in the right atrium. Right atrial myxomas sometimes cause mechanical blockage of the heart valve a condition called tricuspid stenosis and an regular heartbeat, atrial fibrillation.